Two-cycle internal-combustion engine



Oct 15, 1940. H, L lEz-:RHERR TWO-CYCLE INTERNAL COMBUSTION ENGINE Filed June 17, 1958 2 Sheets-Sheet l Oct. 15, 1940- H. LIEBERHERR TWO-'CYCLE INTERNAL COMBUSTION ENGINE 1938 2 Sheets-Sheet 2 Filed June l'?,

BY Pm l] 1D0/@Mam fed/mw ATTORNEYS Patented Oct. l5, 1940 nm ummm, winterthur, switzerland,

assignor to Sulzer Freres, Societe Anonyme, Win thur, Switzerland Application June 17, 1938, Serial No. 214,263 In Switzerland June 19, 1937 claims (ci. 12s-ss) The invention relates to a two-cycle internali; charging-air ports are preferably arranged on combustion engine, in which the scavenging-air, the charging-air, and the supercharging-air are admitted into the working cylinder through ports in the cylinder.

In the engine of the invention both the scavenging and charging-air are admitted into the working cylinder through ports which permit the iiow of gas thereto `only afterA pressure equalization has taken place in the lo working cylinder, whereas the supercharging-air is admitted into the working cylinder under separate control` through ports oppositely disposed in the axial direction of the engine, and extending higher than the exhaust ports and corresponding solely to the amount of supercharging-air admitted. It is known to arrange supercharging air ports throughout the entire cylinder periphery occupied by the exhaust ports. Thesdisadvantage of this arrangement consists in that at the moment where the downwardly moving piston exposes the supercharging air admission ports, the load on one side of the piston is removed causing it to knock in a harmful manner. In the engine of the invention the lateral thrusts on the working piston caused by the combustion gases owing into the chambers situated rearwardly of the supercharging-air admission ports are mutually compensated.

The accompanying drawings illustrate diagrammatically apparatus in accordance with the invention, in which Fig. l is a longitudinal view, partly in section, of the working-cylinder portion of an internal-combustion engine;

Fig. 2 is a crank-shaft diagram of the engine;

Fig. 3 is a cross-section 34 o! Fig. l, and

taken along the line.

Fig. 4 is a cross-section taken along the line 4--4 of Fig. l.

In the apparatus illustrated in the drawings,

the cylinder I is provided with a jacket 2 and a cylinder head 3 in which a fuel-admission valve 4 is mounted. Connected at the air-admission side of the engine is a conduit i for the supply of scavenging-air, charging-air and supercharging-air. The exhaust ports B vand an exhaust conduit (not shown) are connected on ,the oppo- L site side of the cylinder. The scavenging and charging-air `flow directlydnto the working cylinder through ports 1 only after pressure equalization has taken place in the working cylinder, whereas the supercharging-air is admitted into 'as shown in Fig. l,

' opposite sides of the cylinder and may be angul) open, as al result of which scavenging and charging'take place in the working cylinder.

As shown in Fig. 3, the supercharging-alr is i6 admitted under control to the ports 8 through a charging valve III. This valve may be operated in timed relation with the piston in any suitable manner. The advantage of this arrangement is that the waste gases iiowing beyond the supercharging-air ports do not exert unilateral pressure on the piston of the adjacent cylinder. For

each pair of cylinders II and I2, a single feed channel or conduit I3l may be provided for the supercharging air and this may be suitably connected, for example, through the valve Il to the air conduit 5. The lateral thrusts exerted on the working piston and caused by the combustion gases owing into the spaces situated behind the w supercharging-air ports 8 are compensated byA the oppositely disposed ports. l I

yAs shown in Fig. 4, the exhaust ports i and the admission ports 1- are oppositely arranged, and

are offset relatively to each El other in dierent horizontal planes, in .such a manner that when the admission ports 1 open, pressure equalizationhas occurred in cylinder I. For the purpose of preventing the harmful results oi' vibrations in the exhaust conduit, on the scavenging operation, and for', lessening the j length of the web for the purpose of preventing the lining from warping, the exhaust ports I are located in the cylinder in such position that the loweredges thereof are at least 8 percent of the length of the stroke above the lower deadend position of the piston head.

of the cylinder so as to` leave uninterrupted the '55 'half of the periphery.

means i'or guiding the piston springs on the other I claim:

1. In a two-cycle internal-combustion engine having arranged in its cylinder exhaust ports, ports for the admission of scavenging-air, charging-air and supercharging-air, the improvement in which the ports for the admission of supercharging-air are arranged in two groups which are in diametrically opposite sides oi' the cylinder and located above ythe exhaust-ports and the scavenging-'air ports are below-the exing-air ports, said supercharging-air ports being in two groups', each of which is disposed oppositely in the cylinder, conduit means for supplying air under a suitable working pressure to the ports for the admission of scavenging-air and chargair, separate conduit means-supplying air under pressure to the supercharging-air ports, and valve means controlling the now of air through the last mentioned conduit to the super- I charging-air ports in timed relation with the piston.

3. In a two-cycle intemal-combustion engine in which the scavenging-air, .the charging-air andthe supercharging-air enter -the working cylinder through ports, the improvement in which the scavenging-air and the charging-air are introduced into the working cylinder through non-controlled ports which open only after presv oppositely bustion gases into the sure equalization has taken place in the working cylinder, while all the supercharging air enters the working cylinder through controlled ports, disposed, extending higher than the exhaust'ports and corresponding solely tothe amount 'of supercharging-air admitted, in order to compensatethelateral pressures on the working piston resulting from they flowing of the com- J spaces or chambers lying behind the upercharging ports.

4. A two-cycle internal-combustion engine according to claim 3 consisting of at least two cylinders, and .a common supply channel arranged atleast partly between and in direct contact with the adjacent cylinders for introducing supercharging-air into, the supercharging-air ports of thetwo cylinders. v

' 5. A two-cycle internal-combustion engine according-to claim 3, in which the supercharging openings are disposed angularly in order to direct the against the cylinder wall.

8. A two-cycle internal-combustion engine according tp claim 3, in which the exhaust ports are arranged above the scavenging ports and below the supercharging ports.

"I. In a two-cycle internal-combustion engine having arranged in its cylinder exhaust ports,- ports for the admission of lscavenging-air, charging-air, and supercharging-air, the improvement in which the exhaust ports are arranged on one side of the cylinder Vand entirely above the scavenging-air ports a plurality of which are diametrically opposite the exhaust ports, a pluralityof supercharging-air ports in the cylinder located above the exhaust ports, said superderthat a number of the port openings are in .diametrlcally opposite sides ofthe cylinder, and valve means operated in timed relation with the piston for controlling the admission of super. charging-airinto the supercharging-air ports.

HANS I JEBERHERR.

'charging-air ports being so locatedy in the cylin- 

